The present invention relates to closures and methods of making closures for fastening adjacent portions or edges of materials or components together. The closures are useful as fastening system closures for disposable diapers.
Diapers of this general type are widely used. A typical diaper construction comprises an absorbent pad or batt or the like enclosed in an outer plastic shell or a non-woven backsheet that is non-woven fabric laminated with a water impermeable layer such as a polyethylene film. A water permeable inner shell or liner is also provided to promote separation of fluid from the user.
The fastener tape system generally includes adhesive tabs fastened to one end of the diaper assembly construction at each lateral side of the diaper in a permanent xe2x80x9cfactory jointxe2x80x9d by the diaper manufacturer using adhesives or other techniques. The tabs have a face coated with pressure-sensitive adhesive. The tabs are releasably attachable to the other end of the diaper at each lateral side in a xe2x80x9cuser jointxe2x80x9d. The attachment is releasable both to allow permanent removal of the diaper and to allow unfastening to inspect the diaper followed by refastening if indicated.
The user joint may be formed by direct connection of the tab to the diaper outer surface whether the latter is formed of a plastic film or a non-woven backsheet. In the case of plastic film shells, it is typical to provide a xe2x80x9clanding zonexe2x80x9d formed of reinforcing tape or the like for receiving the end of the tab to form the user joint. The landing zone may provide a plastic surface or a non-woven surface and may comprise a knit type fabric landing pad.
The fastener tape system may rely solely upon pressure-sensitive adhesive in the formation of the user joint as shown in U.S. Pat. Nos. 4,795,456, 4,710,190, 4,020,842 and 3,833,456. The use of combined adhesive and mechanical fastener systems is shown in U.S. Pat. Nos. 5,019,065, 5,053,028 and 4,869,724. The teachings of all of these patents being incorporated herein by reference.
The use of extensible or stretchable tabs to promote user comfort through better fit and more secure mounting is also known in the art. The tabs operate as extensible diaper side waistbands. Examples of such diaper fastening systems are disclosed in U.S. Pat. Nos. 4,795,456, 4,066,081, 4,051,853 and 3,800,796.
Related art includes U.S. Pat. Nos. 3,464,094, 4,239,829, 5,250,253 and European Publication No. 0 191 355.
The present invention provides an extensible tab fastener system having a user joint that enables combined mechanical and adhesive attachment. The mechanical and adhesive attachments each contribute to the total integrity or strength of the diaper closure or user joint, and neither has to be fully effective to provide the required total closure strength. The tab fastener system may be produced by high speed manufacturing processes including coextrusion.
In the illustrated embodiments, the fastening system tab members comprise a facestock layer, a contact securement portion comprising a layer of adhesive or cohesive overlying at least a portion of the facestock layer, and mechanical fastening elements projecting from at least a portion of the contact layer. The tab contact securement portion extends over at least a portion of the extensible and substantially nonextensible polymeric portions of the facestock layer. A landing member includes complementary mechanical fastening elements and contact securement portion comprising a contact surface or cohesive for engagement with the tab adhesive or cohesive.